HER2 Testing Market Size & Share Analysis - Growth Trends and Forecast (2026 - 2031)

Global HER2 Testing Market Trends and Insights

HER2-Low Eligibility Expands Tested Population

In January 2025, the FDA approved Roche’s PATHWAY HER2 (4B5) rabbit monoclonal antibody, enabling the identification of HER2-ultralow expression.^{[1]Roche, “PATHWAY HER2 (4B5) Assay Cleared for Ultralow Detection,” roche.com} This significant development expanded the eligibility for trastuzumab deruxtecan to patients previously classified as HER2-negative. Laboratories are now required to differentiate between IHC 0 and 1+, a process that increases slide volumes and drives demand for external proficiency programs. Studies in 2024 revealed only 60–75% agreement among pathologists in HER2-low scoring, prompting the adoption of whole-slide imaging and AI to standardize readings. The rise in retest rates has led to higher reagent consumption and more frequent quality-control runs, contributing to the steady growth of the HER2 testing market.

Tumor-Agnostic HER2-Positive Approvals Widen Testing Across Tumor Types

In March 2026, Japan granted a tumor-agnostic authorization for trastuzumab deruxtecan, requiring pathologists to evaluate HER2 levels across nearly all solid tumors.^{[2]Caris Life Sciences, “Pan-Tumor HER2 IHC Study,” carislifesciences.com} This decision mirrored an FDA tissue-agnostic approval in April 2024, which prompted U.S. oncology centers to incorporate HER2 immunostaining into protocols for colorectal, lung, biliary, and pancreatic cancers. A July 2025 analysis of 65,000 tumors identified actionable HER2 positivity in nearly 10% of bladder and endometrial cancers, highlighting untapped sample volumes.^{[3]American Society of Clinical Oncology, “HER2 Testing Guidelines Update,” ascopubs.org} This expanded testing requirement has driven significant revenue growth for independent reference laboratories, particularly those bundling HER2 with KRAS, BRAF, and MSI markers in comprehensive panels, further strengthening the HER2 testing market.

Guideline-Mandated Testing in Breast and Gastric/GEJ Cancers

The 2024 ASCO/CAP update mandates reflex in situ hybridization for ambiguous IHC 2+ breast tumors and recommends clear reporting of HER2-low status. Gastric cancer guidelines align with this approach, establishing HER2 as a standard treatment for metastatic cases. These directives stabilize baseline testing volumes and justify investments in automated stainers, which, as demonstrated in a 2024 pilot study, can reduce hands-on time by 30–40%. Predictable testing throughput enables laboratories to negotiate favorable reagent volume discounts, a cost-saving measure that supports margin expansion within the HER2 testing market.

Hospital and Lab Infrastructure Upgrades, Automation

To address rising daily case volumes, academic centers and major reference labs are deploying high-capacity IHC robots and FISH processors. In 2025, a validated digital pathology workflow reduced HER2 IHC turnaround times from 48 to 24 hours, enabling same-day treatment planning. Middleware solutions that track fixation times and reagent batches are improving compliance with ISO 15189 standards, an accreditation increasingly required by payers. These operational efficiencies allow facilities to adopt competitive pricing strategies without compromising profitability, expanding access to testing and strengthening the HER2 testing market.

Low-End (0 vs 1+) IHC Reproducibility Challenges

Subtle membrane-staining differences between IHC 0 and 1+ result in variable readings, potentially withholding therapy from eligible patients. A 2024 survey in Sweden indicated that only half of laboratories met proficiency benchmarks on low-expression samples. Variation arises from factors such as cold ischemia, under-fixation, and antibody selection, driving the demand for external quality assessment programs and digital image analysis. These ongoing inconsistencies reduce physician confidence and limit the growth of the HER2 testing market, particularly in resource-constrained regions.

IHC–ISH Discordance and Pre-Analytical Variability

Mismatch between IHC and in situ hybridization occurs when pre-analytical conditions degrade antigenicity or DNA integrity. In 2024, cold ischemia lasting over one hour was identified as a key factor contributing to false negatives. Middleware systems that connect operating-room timestamps to laboratory information systems can alert staff to suboptimal fixation, but adoption remains inconsistent, especially in community hospitals. This variability necessitates reflex testing, which increases costs and delays diagnosis, thereby restricting efficiency improvements in the HER2 testing market.

Segment Analysis

By Test Modality: IHC Anchors Workflow, NGS Gains Share

Guidelines favoring protein visualization on tissue helped immunohistochemistry secure 48.19% of the HER2 testing market's 2025 revenue. Next-generation sequencing, projected to grow at an annual rate of 9.56% through 2031, is being integrated into laboratories' comprehensive panels for ERBB2 copy-number and mutation analysis. The market for NGS-based HER2 testing is set to rise alongside companion-diagnostic labels for zanidatamab and zongertinib. While in situ hybridization is the go-to confirmatory method for ambiguous IHC 2+ cases, its share is declining as AI-enhanced IHC improves first-pass accuracy.

Note: Segment shares of all individual segments available upon report purchase

By Sample Type: Tissue Dominates, Liquid Biopsy Accelerates

FFPE tissue accounted for a dominant 85.19% of the HER2 testing market's 2025 volume, thanks to its longstanding role in histopathology. Tissue, being the gold standard for protein and gene assessment, enjoys robust reimbursement support. While the market size for liquid biopsy in HER2 testing is smaller, it is on a rapid ascent, projected to grow at a 10.56% CAGR through 2031. Plasma-based assays are proving invaluable for inaccessible metastatic lesions and enable serial monitoring without the need for new biopsies.

By Cancer Type: Breast Anchors Demand, Colorectal Surges

Guidelines dictate HER2 assessments for breast cancer from diagnosis to recurrence, leading to breast cancer accounting for 65.19% of the HER2 testing market's 2025 revenue. With trastuzumab deruxtecan's label expansion into the HER2-low category, patients are seeing an uptick in slide counts. Following U.S. approvals of zanidatamab and trastuzumab deruxtecan for ERBB2-amplified metastatic colorectal disease, colorectal cancer is set to experience a 10.32% CAGR growth through 2031. Despite its 3–5% prevalence, the large absolute incidence translates to significant sample numbers.

Note: Segment shares of all individual segments available upon report purchase

By End User: Hospital Labs Lead, Reference Labs Gain Velocity

In 2025, hospital and academic pathology departments secured 47.18% of the HER2 testing market's revenue, thanks to their ability to deliver same-day results to multidisciplinary teams. Strong government reimbursement for in-house IHC tests bolsters capital investments in automated stainers. Independent reference laboratories are on track for a 9.97% growth through 2031, capitalizing on consolidating send-out testing from community hospitals that lack digital pathology capabilities.

In March 2025, NeoGenomics bolstered its national network by acquiring Pathline, enhancing AI-assisted HER2 readings. LabCorp, in May 2025, broadened its offerings to include HER2-ultralow categorization, catering to oncologists seeking precise biomarker resolutions. With their scale, reference labs can negotiate better reagent discounts and establish nationwide logistics, amplifying their margins and solidifying their position in the HER2 testing market.

Geography Analysis

In 2025, North America accounted for 43.12% of the HER2 testing market revenue, driven by extensive insurance coverage and rapid adoption of digital pathology. The U.S. benefits from a consistent pipeline of FDA companion-diagnostic approvals, integrating HER2 assessments into treatment pathways. Meanwhile, Canada's adherence to U.S. guidelines, supported by its publicly funded healthcare system, ensures stable testing volumes.

Asia-Pacific is projected to achieve a 10.43% CAGR through 2031, as regulators in China and Japan expand indications for trastuzumab deruxtecan. China's approval in March 2026 for neoadjuvant breast cancer advances HER2 testing to earlier disease stages, increasing the number of slides required per patient. In 2024, Tata Memorial Centre in India implemented a hub-and-spoke digital pathology model, enabling regional hospitals to access centralized expert readings. South Korea's K-MASTER platform incorporates HER2 testing into a national precision medicine initiative, ensuring reimbursement and promoting standardization.

Europe, guided by consistent ESMO guidelines and ISO quality standards, faces price variability due to differing reimbursement policies, which slows the adoption of premium NGS panels. Germany, France, and the U.K. lead in volume, supported by Roche's CE-marked navify image analysis, which accelerates turnaround times. While Latin America and the Middle East encounter infrastructure challenges, strategic investments in Turkey, Saudi Arabia, and Brazil are establishing new laboratories and expanding the HER2 testing market's reach.